Kali Grosberg, with a group called, "The Mourning Mothers" perform a skit to Iraqi mothers who have mourned the death of family members. Hundreds gather in San Francisco, Calif. on Saturday March 21, 2009, for the, International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Kali Grosberg, with a group called, "The Mourning Mothers" perform...

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Marching up Market Street, protesters join hundreds of others in San Francisco, Calif. on Saturday March 21, 2009 for the International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Marching up Market Street, protesters join hundreds of others in...

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One protester was arrested by San Francisco Police on Polk Street, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 forthe, International Day of Action March on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

One protester was arrested by San Francisco Police on Polk Street,...

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Zachary "Running Wolf" of Berkeley, carries a US flag up-side-down during the march to City Hall, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the, International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Zachary "Running Wolf" of Berkeley, carries a US flag up-side-down...

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San Francisco Police officers keep the peace as pro Israel supporters are kept on one side and pro Palestinian supporters on the other in front of City Hall, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

San Francisco Police officers keep the peace as pro Israel...

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San Francisco Police officers keep the peace as pro Israel supporters are kept on one side and pro Palestinian supporters, Sophia Ibrahim, (right) on the other in front of City Hall, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

San Francisco Police officers keep the peace as pro Israel...

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Pro Israel supporters on one side of Polk Street and pro Palestinian supporters on the other in front of City Hall, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the, International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Pro Israel supporters on one side of Polk Street and pro...

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Protesters march up Market Street, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the, International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Protesters march up Market Street, as hundreds gather in San...

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The San Francisco Police provided security for pro Israel supporters in front of City Hall, as hundreds gather in San Francisco, Calif., on Saturday March 21, 2009 for the, International Day of Action March on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

The San Francisco Police provided security for pro Israel...

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Protesters march up Market Street, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the, International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Protesters march up Market Street, as hundreds gather in San...

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Noor Bondogji, 16-years-old, with the Santa Clara group, Muslim Community Association, at the rally to show supports for all Muslims around the world, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the, International Day of Action March on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Noor Bondogji, 16-years-old, with the Santa Clara group, Muslim...

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Pro Israel supporters on one side of barricades and pro Palestinian supporters on the other in front of City Hall, as hundreds gather in San Francisco, Calif. on Saturday March 21, 2009 for the International Day of Action on the 6th Anniversary of the Invasion of Iraq.

Photo: Michael Macor, The Chronicle

Pro Israel supporters on one side of barricades and pro Palestinian...

Umbrellas mixed with protest signs Saturday in San Francisco, where demonstrators marked the sixth anniversary of the war in Iraq with speeches, chanting and a march up Market Street that stretched about three blocks.

Protesters carried signs about the wars in Iraq and Afghanistan, the Israel-Palestinian conflict, 9/11 conspiracies, jail time for Wall Street bankers, single-payer health care and Proposition 8, the same-sex marriage ban. There were grandmothers for peace, brass bands for peace and dozens of dogs for peace.

The protest remained peaceful, if slightly soggy, until the main group arrived at Civic Center Plaza. There, scores of pro-Israel protesters waving Israeli flags were waiting for the larger contingent, which included many pro-Palestinian protesters.

The pro-Palestinian group broke off from the larger demonstration to confront the Israel supporters, who were carrying signs, including "Hamas, stop using children as human shields." Both sides yelled angrily at each other for a few tense moments near the Polk Street entrance to City Hall, but there were no arrests.

A while later, near the southwest corner of Civic Center Plaza, several shoving matches broke out between protesters and police in riot gear, and two people were arrested. For a time, nearly 100 riot cops with helmets and drawn batons stood in the middle of Polk Street, along with about a dozen police vehicles.

But most of the crowd remained calm and peaceful while a long string of speakers held forth from the stage.

The rest of the larger group of protesters gathered in Civic Center Plaza for a spirited rally. The demonstration coincided with anti-war protests in Washington and Los Angeles.

"It's really important for people around the world to see Americans standing up against this war," said Noel Juan, 52, of the Mission District, as he stood near a 10-foot cardboard figure of Uncle Sam wearing President Obama's likeness.

"Obama has rebranded this war and made it cool for people to wave the flag again," Juan said. "But all the things people hated about Bush are being continued with a slightly different flavor."

Richard Ivanhoe and Cathy Bellin of San Francisco enjoyed the protest from a metal table at Justin Herman Plaza, taking in the "1, 2, 3, 4, we don't want your racist war" chants while snacking on blueberry muffins and coffee.

"My heart goes out to the Iraqi civilians," Bellin said. "The election of Obama doesn't mean we don't have to be here. The war is still happening."

A black-and-white dog named Olive attempted to carry a sign reading "Stop U.S. Aid to Israel" in her teeth - and when she wasn't carrying the sign, she was chewing on it. "She's definitely anti-war," said her owner, Christina Susana.

Much of the protest focused on the economic crisis. One man ran through the crowd dressed as a banker, with fake money spilling out of his hat and briefcase. Judy Greenspan, a third-grade teacher in Richmond who recently received a pink slip, led the crowd at Justin Herman Plaza in a chant, "Jail the rich, bail out the poor, stop the foreclosures, stop the war."

"It's all connected!" she yelled. "It is time for us to take power in this country!"

Members of the anti-war group Code Pink were there, handing out hot-pink stickers reading "Make out, not war" with lipstick prints on them. Gabrielle Faith, 23, wore a handmade pink tutu over her jeans and said Code Pink's message wasn't about one particular war.

"It's about humanity - the women, children and innocent people who are dying," she said.

"I'm sick to my stomach at what's going on in this country," he said. "I'm waiting for the apocalypse. The trumpet helps."

Bruce Yurgil, a cartoonist from San Rafael, was trying to unload 80 homemade T-shirts showing former President George W. Bush's brain spilling from his head. The T-shirts were marked down half-price, to $10.

"It's no fun being a cartoonist these days," he said. "The only person I can make fun of anymore is Rush Limbaugh."